The invention relates broadly to the field of article grippers and, in particular, the invention relates to tool grippers used for tool storage magazines, and to article gripper mechanisms such as part loaders which may be used with machine tools
A variety of article grippers have been used in conjunction with tool handling and part handling machinery, where the tool grippers are often configured as having a pair of fingers or jaws which may be opened and closed in a pincer like movement to grasp the desired article. Most often the gripper fingers are relatively powered with respect to one another by fluid power actuators such as air cylinders. The devices are also frequently fitted with a "fail-safe" mechanism to maintain grasp of the article in the event of a power failure.
The prior art devices are typically of complex construction. having high cost and relatively high maintenance requirements to insure reliability.
Applicants have studied the inherent problems associated with applying article grippers in a variety of spatial orientations, and have determined that modern requirements for machine tools, in particular, dictate that low cost be an objective in the overall design of the device.
Applicants have designed an article gripper which uses certain spring elements arranged in a manner so that the removal force to extract a tool, for instance, from the article gripper is substantially higher than the insertion force to introduce a tool into the gripper.
The design achieved lends itself well to an article gripper made of one-piece homogeneous material such as an engineering plastic, for example, "Delrin" acetal resin.
Further, the design achieved lends itself well to a gripper which may be machined from plastic stock, or which may be readily reproduced through gripper molding techniques such as the plastic injection molding process.
It is therefore an object of the present invention to produce an article gripper having a part removal force which is substantially greater than a part insertion force.
A further object of the present invention is to provide an article gripper which may be constructed of spring devices which are integral with jaw devices.
Still another object of the present invention is to provide an article gripper which may be of one.piece, homogeneous material
Still another object of the present invention is to provide an article gripper which may be either machined or molded according to plastics molding techniques.